Last time I have discussed the construction of dye lasers. Let us discuss the working of dye laser:
The molecules have singlet as well as triplet states. Each electronic state comprises of several vibrational states and each vibrational state comprises of several rotational levels.
Due to absorption of light from pumping source, dye molecules get excited from the ground state E1 to upper vibrational rotational levels of excited state E2 which is upper laser level. Most of the dye molecules decay to the lowest vibrational level L of E2 in a time of about 10-11 seconds. This process is due to thermal redistribution in level E2, thus, it is a non-radiative process. Population inversion is achieved at level L. Continue reading “Working of dye laser”